Fotodiox has announced an interesting new line of lens adapters that make otherwise dumb adapters more functional. In addition to adapting glass, they allow the use of magnetic filters in the adapter and the adjustment of the position of the lens in order to add macro functionality. The use of a magnet to hold a filter in the adapter seems very useful, but I wish the filter was held between the adapter and lens instead of the camera and adapter since the sensor is left largely exposed in Sony cameras. A filter coming loose during a drop could be catastrophic.
Nikon F G-Type Lens to Micro Four Thirds Camera DLX Series Adapter
Amazon
Olympus Zuiko (OM) 35mm SLR Lens to Micro Four Thirds Camera DLX Series Stretch Adapter
Amazon
Canon FD & FL 35mm SLR Lens to Micro Four Thirds Camera DLX Series Stretch Adapter
Amazon
Pentax K Mount (PK) SLR Lens to Micro Four Thirds Camera DLX Series Stretch Adapter
Amazon
Leica R SLR Lens to Micro Four Thirds Camera DLX Series Stretch Adapter
Amazon
Canon EOS (EF / EF-S) D/SLR Lens to Micro Four Thirds Camera DLX Series Stretch Adapter
Amazon
Minolta Rokkor (SR / MD / MC) SLR Lens to Micro Four Thirds Camera DLX Series Stretch Adapter
Amazon
Contax/Yashica (CY) SLR Lens to Micro Four Thirds Camera DLX Series Stretch Adapter
Amazon